North Korea admitted its long-range rocket failed to deliver a satellite into orbit on Friday, and the U.S. condemned the provocative action as a threat to regional security.

Defying international pressure, Pyongyang launched a long range missile on Friday, but U.S. and South Korean officials said it crashed into the sea a few minutes after launch, dealing a blow to the reclusive state.

North Korean soldiers march in Pyongyang on April 12, 2012, as the state's five-day window to launch a rocket opens.AFP

The launch of the three-stage Unha-3 rocket took place at 7:39 A.M. local time, according to South Korean officials. Pyongyang has claimed that the launch was meant to place a communications satellite in space, but the U.S., Japan, South Korea and other nations view it as part of North Korea's attempt to advance its military ballistic missile capacity.

The launch was timed to celebrate the 100th birthday of Kim Il-sung, the deceased founder of the state, and to coincide with the ascent to power of his grandson Kim Jong-un.

Even close ally China had warned against the launch and South Korean intelligence officials have said North Korea may be ready to follow it up with a nuclear test as it did after a rocket launch in 2009, even though it could face more United Nations sanctions if it did.

"The earth observation satellite failed to enter its preset orbit," a newsreader said on North Korea's state TV.

"Scientists, technicians and experts are now looking into the cause of the failure."

It was an unusual admission of failure by the unpredictable regime, since it will be seen by its 23 million people who are only given access to state-controlled news sources. A similarly-failed launch in 2009 was touted by the North as a success.

Friday's launch breached the terms of a recent aid deal struck with the United States as well as United Nations sanctions. Washington, Tokyo and Seoul issued sharp rebukes and said they would step up cooperation and vigilance.

"Despite the failure of its attempted missile launch, North Korea's provocative action threatens regional security, violates international law and contravenes its own recent commitments," White House spokesman Jay Carney said in a statement.

North Korea said it wanted the Unha-3 rocket to put a weather satellite into orbit, although critics believed it was designed to enhance its capacity to design a ballistic missile to deliver a nuclear warhead capable of hitting the continental United States.

The rocket crashed in a sea that separates the Korean peninsula from China off the west coast of South Korea after flying 120 kilometers (75 miles) from its launch site close to the Chinese border, officials in Seoul, Washington and Tokyo said.

A Russian Foreign Ministry official said Friday that North Korea's rocket launch contradicts a UN Security Council resolution restricting the use of ballistic technology, the Interfax news agency said.

Russia had earlier urged Pyongyang not to conduct the launch, saying it would violate a UN Security Council resolution regardless of its purpose and complicate efforts to revive six-party talks over North Korea's nuclear program.

"UN Security Council Resolution No. 1874 demands that the DPRK (North Korea) refrain from any launches using ballistic rockets. This applies to both military and civilian launches," Interfax quoted the Russian official as saying.

The North American Aerospace Defense Command, NORAD, said the first stage fell into the sea west of South Korea, and the remainder of the satellite-carrying missile was deemed to have failed.

"No debris fell on land," NORAD said. "At no time were the missile or the resultant debris a threat.

The world's most militarized border separates North and South Korea and the two states remain technically at war after an armistice ended the Korean War in 1953.

South Korea said it was dispatching ships to try to retrieve the rocket, which it said split into 20 fragments as the first and second stages failed to separate, showing that the new rocket had failed to travel as far as the previous one in 2009.

A Russian observer, a space policy expert from the Russian Academy of Cosmonautics, told Reuters in Pyongyang that long range rocket launches took time to perfect.

"So I would be quite surprised if the third launch of a North Korean rocket would end up in a success, although I believe that they had from 60 to 70 percent chance to successfully put the satellite into orbit," said Yuri Karash.

Later Friday, China called for "calm and restraint" from the international community. "We hope all parties can maintain calm and restraint and avoid doing anything to harm peace and stability on the Korean Peninsula," Foreign Ministry spokesman Liu Weimin said.

Zhang Liangui, an expert on international relations at the Central Party School of the ruling Communist Party, said the apparent failure of Friday's launch and the fact that the rocket did not pass over South Korea or Japan could relieve recent diplomatic tensions.

"I think it's a relief for the international community," Zhang said.

He said the failure of Friday's launch could make North Korea more cautious about conducting a third nuclear test. "But I don't think they will advance or postpone the test," Zhang said.

South Korea warned that North Korea is likely to stage military provocation against the South following its failed long-range rocket launch. "The possibility of an additional long-range rocket launch or a nuclear test, as well as a military provocation to strengthen internal solidarity is very high," a defense ministry official told a parliamentary hearing.

There were no specific indications of military actions from North Korea, the official added.

Haaretz.com, the online edition of Haaretz Newspaper in Israel, and analysis from Israel and the Middle East. Haaretz.com provides extensive and in-depth coverage of Israel, the Jewish World and the Middle East, including defense, diplomacy, the Arab-Israeli conflict, the peace process, Israeli politics, Jerusalem affairs, international relations, Iran, Iraq, Syria, Lebanon, the Palestinian Authority, the West Bank and the Gaza Strip, the Israeli business world and Jewish life in Israel and the Diaspora.